Adra Tunnel (aka The Big Tunnel) is a long tunnel on the Kettle Valley Rail Trail. This spiral tunnel, 489 meters (1604 feet) long, was the longest tunnel on the KVR. The entrances are partially blocked with cement walls to prevent access due to rock falls and some flooding. The Kettle Valley Rail-Trail/ Trans Canada Trail bypasses the tunnel via a short trail. Although it's blocked a short way in due to instability, it's still worth checking out. In Aug 2022, with increased interest in bikepacking the KVR, there were rumours of a restoration project.